Fuel injection control arrangement for internal combustion engines

ABSTRACT

A fuel injection control arrangement for internal combustion engines, wherein a calculating circuit is triggered in response to a signal produced by the fuel-supply timing of the internal combustion engine, which determines the time required for injecting fuel in accordance with the engine operating condition at that time, and at the same time a plurality of gate circuits for controlling the electromagnetic valves associated with the cylinders to be supplied with fuel are selectively controlled in sequence by the signal, characterized in that, when the rotating speed of the engine exceeds a predetermined value, each of the gate circuits is controlled collectively by said signal and the duration for which the gate circuits are actuated is increased.

mite States atent I 1 Hayashi et al. Jan. 1, 1974 FUEL INJECTION CONTROL3,522,794 8/1970 Reichardt 123/32 EA ARRANGEMENT FOR INTERNAL COMBUSTIONENGINES Primary Examiner-Laurence M. Goodridge [75] Inventors: FusaoHayashi; Yasunori Mori, both Attorney-Crag Antonen" Stewart &

of Hitachi, Japan [73] Assignee: Hitachi, Ltd., Tokyo, Japan [57]ABSTRACT [22] Filed: 8, 1971 A fuel injection control arrangement forinternal cornbustlon engines, wherem a calculating clrcuit 1s mg- [21]PP N05 113,268 gered in response to a signal produced by the fuelsupplytiming of the internal combustion engine, [30] Foreign ApplicationPriority Data which determines the time required for injecting fuel Feb6 970 1a an 45/9942 1n accordance with the engine operating cond1t1on atp that time, and at the same time a plurality of gate circuits forcontrolling the electromagnetic valves asso- 123/32 123/119 gg i fciated with the cylinders to be supplied with fuel are I selectivelycontrolled in Sequence y the signal, chap [58] Field of Search 123/32EA, 119 acterized in that, when the rotating speed of the em [56]References Cited gine exceeds a predetermined value, each of the gatecircuits is controlled collectively by said signal and the UNITED STATESPATENTS duration for which the gate circuits are actuated is in-3,699,932 lO/l972 Aono et al l23/32 EA creased, 3,587,536 6/l97l Inoueet al 3,566,846 3/1971 Glockler 123/32 EA 16 Claims, 6 Drawing Figures2o, l6 CALCULAT- ING CKT i: l?

IA AVAL 37 I8 [9 9 PATENTED 1 3. 782 338 CALCULAT- ING CKT INVENTORSFusAo HAYASHI AND lAsuNom Mom Craig, Hn/bnelll Stewart 1 1 MT!) R N 75FUEL INJECTION CONTROL ARRANGEMENT FOR INTERNAL COMBUSTION ENGINES Thepresent invention relates to a so-called fuel injection device in whichthe quantity of fuel to be supplied to an internal combustion engine iselectrically controlled, the fuel being supplied by selectively openingan electromagnetic valve in accordance with the required operation.

In this type of device, the quantity of fuel to be supplied to theinternal combustion engine is determined by the load on the engine, andthe number of revolutions per minute, temperature, etc., of the engine.Accordingly, it is possible to control the-quantity of fuel to besupplied as a function of time by generating electric signalscorresponding to such engine parameters under predetermined relationsand detecting the signals by means of a calculating circuit, producingelectric pulses from the detected signals having a time widthcorresponding to the required fuel supply, and controlling anelectromagnetic valve in response to the electric pulses to regulate thesupply of fuel.

In general, such a fuel injection device is used in multi-cylinderinternal combustion engines, but it is difficult and costly to provideseparate calculating circuits for each of the cylinders,'hence a measureis taken in which an output signal from the calculating circuit isdistributed to a control circuit of the electromagnetic valvecorresponding to the cylinders in which fuel is to be injected.Furthermore, if the distribution is effected for each of the cylindersrespectively, the time width of injection is restricted athigh-speedrotation, so that steps are usually taken by which two or threecylinders with the electromagnetic valves corresponding to each of thecylinders are controlled in one lot, thus avoiding the time restrictiondue to the control responsibility of the electromagnetic valves.However, if it is desired to run the internal combustion engine athigher speed, or to reduce the production cost by reducing the controlresponsibility of the electromagnetic valves, the effect of time widthappears. Due to this effect, the distributing time becomes shorter thanthe injection time width, so that the maximum injection time widthcannot be larger than the distributing time, which may cause a lack infuel supply.

In order to avoid such a disadvantage, if a certain number ofelectromagnetic valves for specific cylinders are to be collectivelycontrolled, the distributing time is widened and the restriction of theinjection time is avoided, but with the fuel injection by such a methodof distribution, the timing is regulated for the suction stroke of asingle cylinder corresponding to a plurality of electromagnetic valveswhich are collected together, and it follows that a fuel injection witha favorable timing for the other cylinders cannot be effected. Such atiming problem can be neglected for intermediate-or high-speed rotation,but when the rotation is effected at low speed or at lower temperatures,it can not be neglected because a phenomenon appears which causes aninstability of rotation of the internal combustion engine affected bythe vaporization factor.

The object of the present invention is to provide a device whicheliminates the inconvenient fuel shortage which causes problems duringhigh-speed operation especially in multicylinder internal combustionengines and which can appropriately respond to a broad range ofoperating characteristics.

Other objects, features and advantages of the invention will becomeapparent from the following description on an embodiment of theinvention illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. la through 1d are fuel controltime charts of the present invention.

FIG. 2 is a block diagram of the fuel injection control arrangementaccording to the invention; and

FIG. 3 is a schematic circuit diagram of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The present invention will bedescribed in detail with reference to the accompanying drawings. Withrespect to the fuel injection time charts shown in FIG. 1, anexplanation will be made for the case of a four-cylinder internalcombustion engine. In a fuel injection method relating to afour-cylinder internal combustion engine in which the ignition order ofthe cylinders is 1-3-4-2 (cylinders), for example, the electromagneticvalves corresponding to the first and the third cylinders are operatedby the suction timing of the first cylinder, and the electromagneticvalves corresponding to the fourth and the second cylinders are operatedby the suction timing of the fourth cylinder. The distributing signalsD, and D are produced by switches operable in synchronism with the crankshaft, and are as shown in FIG. 1a. The distributing signal D opens agate circuit of the electromagnetic valve corresponding to the first andthe third cylinders with a pulse G1, as shown in FIG. 1b, and thedistributing signal D opens a gate circuit of the electromagnetic valvescorresponding to the fourth and the second cylinders with a pulse G4. Atthe same time, build-up voltages of both of the distributing signals Dand D are differentiated and applied to the calculating circuit toexcite it so as to form output signal P shown in FIG. 1c. The outputsignal P is divided into an output P,, which operates theelectromagnetic valve corresponding to the first and the thirdcylinders, and an output P.,, which operates the electromagnetic valvescorresponding to the fourth and the second cylinders. The operationaloutput signal P, when it is made to have a constant time width (actuallyit varies) for the rotating speed of the internal combustion engine,falls within the time width of pulses G and G4 derived from distributingsignals D and D in the intermediate or low speed region (I). However, inpractice the time width of the distributing signals D and D increases ordecreases in inverse proportion to the rotating speed of the engine, sothat it becomes too small for the time width of the operational timesignal P in the high speed region (ll). Accordingly, with this conditionalone, a fuel injection time greater than the time width of thedistributing signals D, and D cannot be obtained.

It is therefore provided in accordance with the present invention, toutilize a distributing means for control in the high speed region (II),by which means the distributing signal D and the gate signals G and Gfor example, are generated synchronously, and the gate pulses G, and Gare widened by an amount G, and G greater than the time width of thedistributing signal D,.

An example of such a control system will be explained with reference tothe block diagram shown in FIG. 2. The output terminal of thecalculating circuit l is connected to the input terminals of the gatecircuits 2 and 3. The calculating circuit l is a conventionalarrangement in fuel injection systems, providing a control output whoseduration depends on various engine conditions. The output P, of gatecircuit 2 is applied to transistor 6 operating the first and the thirdelectromagnetic valve coils 4 and 5, and the output P of gate circuit 3is applied to transistor 9 operating the fourth and the secondelectromagnetic valve coils 7 and 8. Switching devices 10 and 11 producethe distributing signals D and D respectively, which signals areconnected to the input terminals of the distributing circuit 12..Thisdistributing circuit 12 receives the output signal of a speed detector13 which detects the rotating speed of the internal combustion engine.When the value of the output of the detection 13 exceeds a predeterminedvalue, the distributing circuit 12 receives an output signal from thevoltage detector 14, and when the rotating speed of the engine is belowa predetermined value, the distributing circuit merely converts thedistributing signals D and D of the switches 10 and 11 into the gatesignals G and 6,. However, when the speed of the engine is above saidpredetermined value, the circuit 12 generates only the gate signal 6,,and at the same time is switched to extend the time width by G',. Alsoat the moment of such a switching, the pulse generator 15 receives anoutput signal from the voltage detector 14 and generates a correctingsignal P, and applies this signal to the transistor 9, independent ofthe gate circuit 3, to operate the electromagnetic valve coils 7 and 8.This is done, when the stage of the distributing circuit is changedimmediately after the issue of the distributing signal D of the switchdevice 10, to ensure that the gate circuit 3 is not opened until thenext distributing signal D is generated, and accordingly, fuel injectionfor the fourth and the second cylinders are omitted for one time, asseen in FIG. 1b.

An exemplary embodiment will be described with respect to an electricalcircuit diagram shown in FIG. 3. The output terminal of the calculatingcircuit 1 is connected to the base of a PNP type transistor 6 through 1series connected resistor 16 and diode l7 successively, and is furtherconnected to the base of an NPN type transistor 9 through a resistor 18and a diode 19. The emitters of both of the transistors 6 and 9 aregrounded, and the collectors are connected respectively to theelectromagnetic valve coils 4 and 5 and the electromagnetic valve coils7 and 8 through resistors 20 and 21 thus forming a switching circuit fora current flowing therein.

A switch 10 is inserted between the resistor 23 connected to the powersource line 22 and ground, the connecting point of the resistor 23 ofthe switch 10 is connected as a trigger input of the calculating circuit1 through a differential circuit, comprising a condenser 24 and aresistor 25, and a diode 26, and at the same time is connected to thebase of an NPN type transistor 29 through a diode 27 and a resistor 28.This transistor 29, which is used for reversing the characteristic, hasits emitter grounded and its collector connected to the source line 22.At the same time the collector of transistor 29 is connected to the baseof an NPN type transistor 32 through a resistor 31; The emitter of thistransistor 32 is grounded, and the collector is connected to the powersource line 22 through a resistor 33 and to the intermediate pointbetween the resistor 16 and the diode 17 through a diode 34. During theconducting state of this transistor 32, the base circuit of thetransistor 6 is grounded thereby to close the gate.

Another switch 11 for providing a distributing signal is insertedbetween the emitter of an NPN type transistor 35 and ground, and thecommon connecting point with the emitter is connected as a trigger inputof said calculating circuit 1 through a differential circuit consistingof a condenser 36, a resistor 37 and a diode 38. The collector of thetransistor 35 is connected to the power source line 22 through aresistor 39, and at the same time is connected to an intermediateconnecting point between the resistor 18, said diode 19 and the diode 57through a diode 40 so as to constitute a gate circuit for the basecircuit of the transistor 9. The base of the transistor 35 is connectedto the collector of a PNP type transistor 42 through a resistor 41, andwhen the rotating speed of the internal combustion engine is within thepredetermined value, it is biased forwardly.

With such a circuit, when the switching devices 10 and 11 are closed,the transistors 32 and 35 are in the conductive state respectively, thebase circuit of the transistors 6 and 9 are in a grounded state throughthe diodes 34 and 40 and the gate is closed. When, for example, theswitching device 10 is opened, the transistor 29 becomes conductive, andthe transistor 32 becomes non-conductive, and the gate of the transistor6 is opened. At the same time the calculating circuit 1 is triggeredthrough the differential circuit consisting of the condenser 24 and thecondenser 25; thus, an operational output is produced, providing forconducting of the transistor 6 whose gate is opened, thereby passing acurrent through electromagnetic valve coils 4 and 5 to inject fuel.

When the switch 10 is closed, and then the switch 11 is opened, theemitter of the transistor 35 is separated from ground, so that itbecomes non-conductive. Accordingly, the gate of the transistor 9 isopened, and at the same time, the calculating circuit 1 is triggeredthrough the differential circuit consisting of the condenser 36 and theresistor 37. Thus, an output is generated from calculating circuit 1,transistor 9 becomes conductive and the electromagnetic valve coils 7and 8 are energized. Such fuel injection control is a fundamental to theoperation in the region (I) controlling the first and the thirdcylinders, as well as the fourth and the second cylinders separatelywhen the rotating speed of the internal combustion engine is below thepredetermined value.

Now the fuel injection in the high-speed region (II) will be described.The numeral 43 designates a rotating speed detector associated with theinternal combustion engine, in which an output voltage is generatedwhich is proportional to the rotating speed by means of atacho-generator, or the like, and is so connected that said voltage isapplied to the emitter of the NPN type transistor 45 through a diode 44,and at the same time this emitter is grounded through a resistor 46. Thenumeral 47 designates a potentiometer-type resistor connected betweenthe power source line 22 and ground, and the voltage-dividing terminalis connected to the base of said transistor 45 through a resistor 48,thereby supplying a forward biassing voltage thereto. The emitter ofsaid transistor 42 is connected to the power source line 22, the base isconnected to the collector of the transistor 45 through a resistor 49,and the collector is connected to the base of the transistor 45 througha resistor 50. At the same time the collector of transistor 42 isgrounded through a series combination of resistors 51 and 52. Theemitter of said transistor 45 is backwardly biassed by a voltageproportional to the rotating speed of the internal combustion engine,and the base is forwardly biassed by the divided voltage of the resistor47, so that a level detecting circuit is formed.

When the rotating speed of the engine is lower than the predeterminedvalue, the transistor 45 is in a conductive state, and when the speed ishigher than the predetermined value, it is in a non-conductive state.The transistor 42 is in the same conductive state as the transistor 45;the resistor 50 connected between the collector and the base of thetransistor 45 serves to regulate the hysteresis characteristics of thedetecting circuit. The numeral 53 designates an NPN type transistor, andthe base is connected to the intermediate point between the resistors 51and 52. The emitter of transistor 53 is grounded, andthe collector isconnected to the power source line 22 through a resistor 54; and at thesame time the collector is connected to the base of an NPN typetransistor 56 through a diode 55.

The emitter of this transistor 56 is connected to the collector of thetransistor 32, and the collector is connected to the intermediateconnecting point between the resistor 18 connected to the base of thetransistor 9 and the diode 19 through a diode 57. Thus, when the base ofthis transistor 56 is in a forwardly biassed state, the gate circuit ofthe transistor 9 operates in synchronism with the operation of thetransistor 32. The collector of the transistor 53 is connected as adischarge circuit fora condenser 60 for extending the gate time widththrough a diode58 and a resistor 59. One end of this condenser 60 isgrounded, and the other end is connected to the base of the transistor29 through resistors 61 and 28. In this example, condenser 60 isconnected to the output terminal of the diode 27, but by selecting thevalue of the resistor 59 to have a small value, and by selecting thevalue of the resistor 61 to be large, thus to quicken the discharge ofthe condenser 69 in the conductive state of the transistor 53, when thetransistor 53 is in a non-conductive state, the discharge is prolongedby the base current (small) of the transistor 29. On the other hand forthe period during which the transistor 29 is non-conductive (period whenthe gate is closed), when the transistor 53 is in a non-conductivestate, the discharge of condenser 60 is a little more prolonged than theclosing period of the switching device 10.

With such a circuit, when the rotating speed of an internal combustionengine is below a predetermined value, the output voltage of therotating speed detector 43 is also small, so that the emitter-base ofthe transistor 45 is biassed forwardly and is in a conductive state, andtherefore the transistors 42 and 53 are in the conductive state. Thusthe discharging time constant of the condenser 60 is sufficiently small,and the operation of the transistor follows the switching device 10.Also, the base of the transistor 56 is grounded and is in anonconductive state, and further, the base of the transistor 35 is inthe conductive state since it is forwardly biassed by the collectorpotential of the transistor 42, so that the transistor 35 also followswith the operation of the switching device 11.

However, when the rotating speed of the internal combustion engineexceeds the predetermined value, the emitter potential of the transistor45 becomes high, causing it to become non-conductive, so that thetransistors 42 and 53 are biased to the non-conductive state.Consequently, a part of the discharge circuit of the condenser (the partwhere the time constant is small) is separated, so that the dischargeforms the base current of the transistor 29. Thus, the period when thetransistor 29 is non-conductive is prolonged with respect to the closingof the switching device 10. This prolonged time is the above-said gatetime width G',, G'.,. Further, the base bias of the transistor 35disappears as the transistor 42 becomes non-conductive, so that it alsois biased to the non-conductive state, and the divided signal D, fromthe switch 11 cannot be obtained anymore. But at the same time withthis, the

transistor 56 becomes conductive, and the gate in the gate circuit ofthe transistor 9 is controlled by the switch 10 together with the othertransistor 6.

Next, a description will be made of the fuel injection correction insuch a switching operation. The transistor 62 forms a switching elementfor producing a correcting signal P'.,. This transistor 62 is of the NPNtype, the emitter is grounded, and the collector is connected to thepower source line 22 through a resistor 63. At the same time thecollector of transistor 62 is connected to the base of the transistor 9through a diode 64. The base is connected to the power source line 22through a resistor 65 to provide a forward biassing, and at the sametime is connected to the collector of the transistor 42 through acondenser 66, thus causing the transistor 62 to become non-conductivetemporarily at the switching whereby the transistor 9 is madeconductive.

Namely, in the region (I), since the transistor 42 is in a conductivestate, the condenser 66 is charged with a polarity as indicated, and thetransistor 62 is forwardly biased through the resistor 65, so that it isin a conductive state. But when the operation is transferred to region(II), and as the transistor 42 becomes nonconductive, the lowering ofvoltage at the collector lowers the base potential of the transistor 62through the condenser 66 and makes it non-conductive. The period of thisnon-conductive state is the period during which the condenser 66 isdischarged and the base potential is restored to the original state.When the transistor 62 becomes non-conductive, the collector potentialis increased and it is applied to the base of the transistor 9 throughthe diode 64 causing it to become con ductive.

In the above-described example, the switching of the region (II) is usedonly for detecting the rotating speed of the internal combustion engine,but in practice, variation in the injecting quantity due to the load ofthe 'internal combustion engine, and the variation in the injectingquantity due to the temperature of the internal combustion engine arethe factors determining the time width of the operating output P, sothat when such conditions are put into the condition of the switching,more appropriate control can be expected.

We claim:

1. In a fuel injection control arrangement for controlling the fuelsupplied to plural cylinders of an internal combustion engine inresponse to engine conditions comprising calculating means forgenerating gating pulses having a duration corresponding to the fuelinjection time required under detected engine conditions,

a plurality of injection valves, each injection valve controlling thefuel injection of a respective engine cylinder,

a plurality of gates, each gate applying said gating pulses to arespective group of injection valves so as to actuate said injectionvalves in groups in response to said calculating means,

distributing means responsive to the speed and timing of said engine foractuating said gates sequentially when the rotating speed of saidinternal combustion engine is below a predetermined value andcollectively with the same timing when said rotating speed exceeds saidpredetermined value, and

speed detecting means coupled to said distributing means, having ahysteresis characteristic characterized in that said arrangement isprovided with a pulse generator for supplying pulses into a group ofinjection valves independent of the gating pulses from the calculatingmeans, in response to the speed detecting means when the engine rotatingspeed changes from a value below said predetermined level to a valueexceeding said predetermined value.

2. A fuel injection control arrangement according to claim 1, whereinsaid gates are actuated by said distributing means for given timeperiods which are of greater duration than the duration of said gatingpulses when said rotating speed is below said predetermined value, saiddistributing means including means for increasing the duration of saidgiven time periods during which said gates are actuated by saiddistributing means when said rotating speed exceeds said predeterminedvalue.

3. A fuel injection control arrangement according to claim 1, whereinsaid distributing means includes timing means responsive to the enginetiming for generating cycle timing signals for each of said gates, adistributing circuit for normally applying said cycle timing signals tothe respective gates to which they pertain in sequential order, and saidspeed detecting means includes speed responsive control means foractuating said distributing circuit to apply each of said cycle timingsignals to all of the gates when said rotating speed exceeds saidpredetermined value.

4. A fuel injection control arrangement according to claim 3, whereinsaid timing means includes a plurality of switching devices responsiveto engine rotation for generating said cycle timing signals in asequential order.

5. A fuel injection control arrangement according to claim 4, whereinsaid speed responsive control means includes a speed detector providinga signal having a level proportional to the rotating speed of saidengine and a level detector providing a control output when the outputlevel of said speed detector exceeds a predetermined value.

6. A fuel injection control arrangement for controlling the fuelsupplied to plural cylinders of an internal combustion engine inresponse to engine conditions comprising calculating means forgenerating gating pulses having a duration corresponding to the fuelinjection time required under detected engine conditions,

a plurality of injection valves, each injection valve controlling thefuel injection of a respective engine cylinder,

a plurality of gates, each gate applying said gating pulses to arespective group of injection valves so as to actuate said injectionvalves in groups in response to said calculating means, and

than the duration of said gating pulses when said rotating speed isbelow said predetermined value, said distributing means including meansfor in-" creasing the duration of said given time periods during whichsaid gates are actuated by said distributing means when said rotatingspeed exceeds said predetermined value wherein said distributing meansincludes pulse generating means for supplying pulses into a selectedgroup of injectionvalues independent of the gating pulses from saidcalculating means when said engine speed changes from a value below saidpredetermined value to a value exceeding said predetermined value.

7. A fuel injection control arrangement according to claim 6, whereinsaid pulse from said pulse generating means operate at least one of saidgates for up to one gate operating period when said rotating speedchanges from a value below said predetermined value to a value exceedingsaid predetermined value.

8. A fuel injection control arrangement according to claim 6, whereinsaid distributing means includes timing means responsive to the enginetiming for generating cycle timing signals for each of said gates, adistributing circuit for normally applying said cycle timing signals tothe respective gatesto which they pertain in sequential order, and speedresponsive control means for actuating said distributing circuit toapply each of said cycle timing signals to all of the gates when saidrotating speed exceeds said predetermined value.

9. A fuel injection control arrangement for controlling the fuelsupplied to plural cylinders of an internal combustion engine having aplurality of injection valves and associated valve actuator means forcontrolling the supply of fuel to said cylinders in response to engineconditions comprising:

first means for generating gating pulses having a duration correspondingto fuel injection time re quired under detected engine conditions;

a plurality of gates coupled to said injection valve actuator means forapplying said gating pulses to a respective group of injection valveactuator means, so as to actuate said injection valves in groups inresponse to said first means; and

second means, responsive to the speed and timing of said engine, foractuating said gates sequentially for respective periods of timecorresponding to the duration of said gate pulses when the rotatingspeed of said internal combustion engine is below a predetermined valueand collectively with the same timing of a duration longer than theduration of said gate pulses when said rotating speed is at least equalto said predetermined value characterized in that said arrangement isprovided with a pulse generator for supplying pulses into a group ofinjection valves independent of the gating pulses, in response to thespeed detecting means when the engine speed changes from a value belowsaid predetermined level to a value at least equal to said predeterminedvalue.

10. A fuel injection control arrangement according to claim 9, whereinsaid second means includes a gate control circuit coupled to said gatesfor enabling the supply of said gating pulses from said first means tosaid gates when said engine speed is below said predetermined speed andfor supplying a prolonged gate actuating signal, having a durationlonger than the duration of said gating pulses, to said gates,simultaneously, when said rotation speed has reached a value at leastequal to said predetermined value.

11. A fuel injection control arrangement according to claim 10, whereinsaid gate control circuit includes a variable time constant circuit forgenerating a first gate control signal of a first prescribed durationfor enabling said gating pulses to be supplied to said gates and forgenerating a second gate control signal of a second prescribed durationfor enabling said prolonged gate actuating signal to be supplied to saidgates.

12. A fuel injection control arrangement according to claim 11, whereinsaid gate control circuit includes a first switching circuit, responsiveto the speed of said engine lying within one of first and secondprescribed engine speed ranges, for enabling the generation of saidfirst gate control signal when said engine speed is below saidpredetermined speed and for enabling the generation of said second gatecontrol signal when said engine speed has reached a value at least equalto said predetermined speed.

13. A fuel injection control arrangement according to claim 12, whereinsaid gate control circuit further includes a second switching circuit,responsive to the state of said first switching circuit, for enablingthe supply of said prolonged gate actuating signal to all of said gatessimultaneously, when said engine speed has reached a value at leastequal to said predetermined speed.

14. A fuel injection control arrangement according to claim 13, whereinsaid first means further includes first and second timing circuitsresponsive to the rotation of said engine for generating first andsecond timing signals for initiating the generation of said gatingpulses.

15. A fuel injection control arrangement according to claim 14 whereinsaid gate control circuit further includes third and fourth switchingcircuits, responsive to the outputs of respective ones of said timingcircuits and the speed of said engine, for coupling gate pulses and saidprolonged gate actuating signal to said gates.

16. In a fuel injection control arrangement for controlling the fuelsupplied to plural cylinders of an internal combustion engine inresponse to engine conditions 1 comprising calculating means forgenerating gating pulses having a duration corresponding to the fuelinjection time required under detected engine conditions,

a plurality of injection valves, each injection valve controlling thefuel injection of a respective engine cylinder,

a plurality of gates, each gate applying said gating pulses to arespective group of injection valves so as to actuate said injectionvalves in groups in response to said calculating means, and

distributing means responsive to the speed and timing of said engine foractuating said gates sequentially when the rotating speed of saidinternal combustion engine is below .a predetermined value, said gatesbeing actuated bysaid distributing means for given time periods whichare of greater duration than the duration of said gating pulses whensaid rotating speed is below said predetermined value, said distributingmeans including means for increasing the duration of said given timeperiods during which said gates are actuated by said distributing meanswhen said rotating speed exceeds said predetermined value,

characterized in that a speed detecting means having a hysteresischaracteristic is coupled to said distn'buting means to control thespeed respective input thereto and said arrangement is provided with apulse generator for supplying pulses into a group of injection valvesindependent of the gating pulses, in response to the speed detectingmeans when the engine speed changes from a value below saidpredetermined level to a value exceeding said predetermined value.

1. In a fuel injection control arrangement for controlling the fuelsupplied to plural cylinders of an internal combustion engine inresponse to engine conditions comprising calculating means forgenerating gating pulses having a duration corresponding to the fuelinjection time required under detected engine conditions, a plurality ofinjection valves, each injection valve controlling the fuel injection ofa respective engine cylinder, a plurality of gates, each gate applyingsaid gating pulses to a respective group of injection valves so as toactuate said injection valves in groups in response to said calculatingmeans, distributing means responsive to the speed and timing of saidengine for actuating said gates sequentially when the rotating speed ofsaid internal combustion engine is below a predetermined value andcollectively with the same timing when said rotating speed exceeds saidpredetermined value, and speed detecting means coupled to saiddistributing means, having a hysteresis characteristic characterized inthat said arrangement is provided with a pulse generator for supplyingpulses into a group of injection valves independent of the gating pulsesfrom the calculating means, in response to the speed detecting meanswhen the engine rotating speed changes from a value below saidpredetermined level to a value exceeding said predetermined value.
 2. Afuel injection control arrangement according to claim 1, wherein saidgates are actuated by said distributing means for given time periodswhich are of greater duration than the duration of saiD gating pulseswhen said rotating speed is below said predetermined value, saiddistributing means including means for increasing the duration of saidgiven time periods during which said gates are actuated by saiddistributing means when said rotating speed exceeds said predeterminedvalue.
 3. A fuel injection control arrangement according to claim 1,wherein said distributing means includes timing means responsive to theengine timing for generating cycle timing signals for each of saidgates, a distributing circuit for normally applying said cycle timingsignals to the respective gates to which they pertain in sequentialorder, and said speed detecting means includes speed responsive controlmeans for actuating said distributing circuit to apply each of saidcycle timing signals to all of the gates when said rotating speedexceeds said predetermined value.
 4. A fuel injection controlarrangement according to claim 3, wherein said timing means includes aplurality of switching devices responsive to engine rotation forgenerating said cycle timing signals in a sequential order.
 5. A fuelinjection control arrangement according to claim 4, wherein said speedresponsive control means includes a speed detector providing a signalhaving a level proportional to the rotating speed of said engine and alevel detector providing a control output when the output level of saidspeed detector exceeds a predetermined value.
 6. A fuel injectioncontrol arrangement for controlling the fuel supplied to pluralcylinders of an internal combustion engine in response to engineconditions comprising calculating means for generating gating pulseshaving a duration corresponding to the fuel injection time requiredunder detected engine conditions, a plurality of injection valves, eachinjection valve controlling the fuel injection of a respective enginecylinder, a plurality of gates, each gate applying said gating pulses toa respective group of injection valves so as to actuate said injectionvalves in groups in response to said calculating means, and distributingmeans responsive to the speed and timing of said engine for actuatingsaid gates sequentially when the rotating speed of said internalcombustion engine is below a predetermined value, said gates beingactuated by said distributing means for given time periods which are ofgreater duration than the duration of said gating pulses when saidrotating speed is below said predetermined value, said distributingmeans including means for increasing the duration of said given timeperiods during which said gates are actuated by said distributing meanswhen said rotating speed exceeds said predetermined value wherein saiddistributing means includes pulse generating means for supplying pulsesinto a selected group of injection values independent of the gatingpulses from said calculating means when said engine speed changes from avalue below said predetermined value to a value exceeding saidpredetermined value.
 7. A fuel injection control arrangement accordingto claim 6, wherein said pulse from said pulse generating means operateat least one of said gates for up to one gate operating period when saidrotating speed changes from a value below said predetermined value to avalue exceeding said predetermined value.
 8. A fuel injection controlarrangement according to claim 6, wherein said distributing meansincludes timing means responsive to the engine timing for generatingcycle timing signals for each of said gates, a distributing circuit fornormally applying said cycle timing signals to the respective gates towhich they pertain in sequential order, and speed responsive controlmeans for actuating said distributing circuit to apply each of saidcycle timing signals to all of the gates when said rotating speedexceeds said predetermined value.
 9. A fuel injection controlarrangement for controlling the fuel supplied to plural cylinders of aninternal combustion engine having a plurality of Injection valves andassociated valve actuator means for controlling the supply of fuel tosaid cylinders in response to engine conditions comprising: first meansfor generating gating pulses having a duration corresponding to fuelinjection time required under detected engine conditions; a plurality ofgates coupled to said injection valve actuator means for applying saidgating pulses to a respective group of injection valve actuator means,so as to actuate said injection valves in groups in response to saidfirst means; and second means, responsive to the speed and timing ofsaid engine, for actuating said gates sequentially for respectiveperiods of time corresponding to the duration of said gate pulses whenthe rotating speed of said internal combustion engine is below apredetermined value and collectively with the same timing of a durationlonger than the duration of said gate pulses when said rotating speed isat least equal to said predetermined value characterized in that saidarrangement is provided with a pulse generator for supplying pulses intoa group of injection valves independent of the gating pulses, inresponse to the speed detecting means when the engine speed changes froma value below said predetermined level to a value at least equal to saidpredetermined value.
 10. A fuel injection control arrangement accordingto claim 9, wherein said second means includes a gate control circuitcoupled to said gates for enabling the supply of said gating pulses fromsaid first means to said gates when said engine speed is below saidpredetermined speed and for supplying a prolonged gate actuating signal,having a duration longer than the duration of said gating pulses, tosaid gates, simultaneously, when said rotation speed has reached a valueat least equal to said predetermined value.
 11. A fuel injection controlarrangement according to claim 10, wherein said gate control circuitincludes a variable time constant circuit for generating a first gatecontrol signal of a first prescribed duration for enabling said gatingpulses to be supplied to said gates and for generating a second gatecontrol signal of a second prescribed duration for enabling saidprolonged gate actuating signal to be supplied to said gates.
 12. A fuelinjection control arrangement according to claim 11, wherein said gatecontrol circuit includes a first switching circuit, responsive to thespeed of said engine lying within one of first and second prescribedengine speed ranges, for enabling the generation of said first gatecontrol signal when said engine speed is below said predetermined speedand for enabling the generation of said second gate control signal whensaid engine speed has reached a value at least equal to saidpredetermined speed.
 13. A fuel injection control arrangement accordingto claim 12, wherein said gate control circuit further includes a secondswitching circuit, responsive to the state of said first switchingcircuit, for enabling the supply of said prolonged gate actuating signalto all of said gates simultaneously, when said engine speed has reacheda value at least equal to said predetermined speed.
 14. A fuel injectioncontrol arrangement according to claim 13, wherein said first meansfurther includes first and second timing circuits responsive to therotation of said engine for generating first and second timing signalsfor initiating the generation of said gating pulses.
 15. A fuelinjection control arrangement according to claim 14 wherein said gatecontrol circuit further includes third and fourth switching circuits,responsive to the outputs of respective ones of said timing circuits andthe speed of said engine, for coupling gate pulses and said prolongedgate actuating signal to said gates.
 16. In a fuel injection controlarrangement for controlling the fuel supplied to plural cylinders of aninternal combustion engine in response to engine conditions comprisingcalculating means for generating gating pulses having a durationcorresponding to the fuel injection time required under detected engineconditions, a plurality of injection valves, each injection valvecontrolling the fuel injection of a respective engine cylinder, aplurality of gates, each gate applying said gating pulses to arespective group of injection valves so as to actuate said injectionvalves in groups in response to said calculating means, and distributingmeans responsive to the speed and timing of said engine for actuatingsaid gates sequentially when the rotating speed of said internalcombustion engine is below a predetermined value, said gates beingactuated by said distributing means for given time periods which are ofgreater duration than the duration of said gating pulses when saidrotating speed is below said predetermined value, said distributingmeans including means for increasing the duration of said given timeperiods during which said gates are actuated by said distributing meanswhen said rotating speed exceeds said predetermined value, characterizedin that a speed detecting means having a hysteresis characteristic iscoupled to said distributing means to control the speed respective inputthereto and said arrangement is provided with a pulse generator forsupplying pulses into a group of injection valves independent of thegating pulses, in response to the speed detecting means when the enginespeed changes from a value below said predetermined level to a valueexceeding said predetermined value.